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Six Sigma methodologies in combination with Lean thinking have made considerable inroads as continuous improvement tools initially in manufacturing and more recently for service and transactional processes. There is considerable interest globally in training professionals on the use and application of these tools appropriate to either operational or transactional areas. It has long been realized that adult learning is at its best when participants are involved in relevant “hands-on” experiments. Six Sigma training has seen the use of class room demonstrations ranging from the use of playing cards, simulations and to the use of sophisticated experiments to illustrate concepts of factorial designs. This paper will focus on a series of simple but modular experiments that were developed over the past two years illustrating the application of all the Statistical tools that are taught as a part of Six Sigma Green and Black Belt body of knowledge.

This paper presents two new methods to quantitatively evaluate the mechanical durability of multi-layered automotive paint systems. The first examines the resistance of the paint system to particle impacts and involves the impact of hard particles against the painted surface, under controlled conditions. The second test examines the resistance of the clearcoat layer in the paint system to surface abrasion, or mar. The test uses a steel sphere which is rotated against the paint surface in the presence of a slurry of fine abrasive particles. These two techniques have been successfully applied to a set of commercial automobile paints, and were found to discriminate well between them and give reproducible, quantitative data. The effects of the bake conditions on both the erosion and abrasion resistance of a full paint system and the abrasion resistance of a range of commercial clearcoats are examined in detail.

Design and implementation of predictive service life performance tests also referred to as “Key Life Tests” are vital to the automotive industry to control warranty costs, track the quality of materials and processes, and in the specification of new materials systems. In addition to these roles, key life tests offer valuable insights into relating design features to performance and serving as tools to predict durability. A systems approach to assess durability of painted automotive exteriors subject to various tribological loading conditions is presented in this paper. This approach blends fundamental phenomenological understanding with real world usage “metrics” in order to implement laboratory simulations. To the authors knowledge, this is the first time, a synthesis of tribological principles and systems theory have been made for designing and implementing key life tests for paint durability. Several examples have been included to bring out the power of this approach.

Durability tests have been initiated on olefinic and production painted fascias. Both 2D and 3D tests have provided insights into Friction Induced Damage (FID) failure mechanics. Full scale, 3D tests of automotive fascia mimic the parking lot rubbing contact between cars with friction forces exceeding 5000. N. 2D tests provide the cost effective approach to materials research by isolating the failure mechanics in the upper 250 μm of the decorated TPO where the cosmetic damage is initiated. Initial findings show some olefinic paint, TPO combinations to be more damage resistant for realistic frictional contact scenarios.

The automotive industry in the past few years is experiencing a significant growth in the application of highly engineered plastics, particularly in bumper fascia applications. It is now very common to find one of several variations in Thermoplastic Polyolefins used as the base material (substrate) for bumper fascias. Durability of painted TPO's to various service life conditions is a matter of significant concern to the automobile manufacturer. Erosion durability of painted plastics (particularly bumper fascias) in a touch free car wash environment, where the surface is subjected to high-pressure water jets cycle is matter of concern to the automobile manufacturer. In addition, there is also a concern in self-serve car wash stations equipped with high-pressure water jets. This paper reports a part of a major study that was undertaken to address this title subject.

Engineered injection molded thermoplastic polyolefins are now common substrates of choice for painted automotive bumper fascias. A major concern with painted plastics involves susceptibility to surface damage in the shop floor, during transit and in service life. Preliminary failure analysis of field specimens points out the damage in majority of the cases to be “cohesive”, within the near surface regions of the substrate. This paper describes the application of a second-generation computer controlled instrumentation, which simulates Friction Induced Damage (FID) similar to those observed in the field. It has been recognized in several earlier works, that FID is a complex phenomenon and is a function of number of tribological and environmental variables. Since the material systems are viscoelastic, FID is also a strong function of temperature and the dynamic mechanical properties of the coating and substrate.

Electrochemical Impedance Spectroscopy (EIS) and Thermal Wave Imaging (TWI) are complementary techniques which can be used to detect and estimate Impact Induced Corrosion (IIC) at the metal-polymer interface. This paper describes the use of the above techniques to detect Impact Induced Corrosion in a variety of pre-coated and painted sheet steels. It has been possible to show, that IIC is a threshold phenomenon and depends on the type of galvanized coating. Evaluation of IIC, using a high performance indoor accelerated test and preliminary data from the proving grounds are presented in this paper.

Stone impact damage to automotive paint finishes has drawn significant attention in recent years from both automobile manufacturers and their OEM paint suppliers. This work describes the design and implementation of a precision instrumented impact device to perform a wide range of phenomenological studies of impact processes. A precision launch mechanism, control of the appropriate impact and environmental variables, a versatile sample holder, and optional advanced instrumentation render this device useful both as a quality control bench marking tool and as an instrument to design improved impact resistant coating systems.

Cosmetic corrosion of painted automotive substrates is a complex phenomenon being a function of number of environmental variables and material properties. To address the need for reliable accelerated corrosion tests, a high performance corrosion chamber was built by VOLVO car corporation, Gothenberg, Sweden. Using a statistically designed program of experiments, excellent correlation between outdoor and laboratory simulations have been established using the VOLVO technique. Traditional methods for corrosion data analysis has been based on the use of well known statistical methods. In this paper, we have introduced Artificial Neural Networks (ANN) to study and establish complex relations between scribe creep data and the variables that govern cosmetic corrosion performance. Application of the ANN methodology as a predictive tool has been discussed.

Automotive car bodies are subject to impact damage by stones lofted by front tires or from passing vehicles. Velocities of stone impact can reach values much higher than the moving automobile. Stone impact damage can result in paint loss and a possible corrosion problem due to damage at the metal-polymer interface. This work describes the application of several complementary techniques to evaluate impact damage. These techniques include Electrochemical Impedance Spectroscopy (EIS), Thermal Wave Imaging (TWI) and Acoustic Microscopy (AM) The advantages offered by each technique are discussed.